The cargo carrying portion of vans and trailers are typically closed by panel doors which may be located to the rear or to the side. These panel doors are usually hinged to open outwardly and to provide access to the interior of the van or trailer. It is desirable to positively close and to lock or latch these doors when entrance into the interior of the truck or trailer is not required during shipment of the items therewithin. An additional reason for maintaining the panel doors of such vans and trailers positively latched arises when the contents are maintained at lower temperatures. The panel doors of refrigerated vans and trailers often carry seals or gaskets which are effective only if the doors are tightly latched. Even on nonrefrigerated vehicles latching of the panel doors is usually desirable to prevent the entry of rain, water or other foreign substances into the interior.
Typical prior art latching mechanisms for panel doors in vans or trailers are generally shown in U.S. Pat. No. 4,127,291. The latching mechanisms of this patent, which are similar to those available from Eberherd Manufacturing Company of Cleveland, Ohio, include a vertical member, such as a rod or pipe, which is mounted to the door by appropriate bearing members so that the pipe is journaled for rotation while held on the door. The opposed ends of the pipe upper and lower cam or, which extend beyond the upper and lower door edges, carry latch members. Mounted to the van or trailer frame or body, so as to be adjacent to the upper and lower cam or latch members when the doors are closed are upper and lower keepers. When the doors are fully closed, the cam or latch members overlie and are adjacent to the keepers. Rotation of the pipe causes the cam or latch members to interact with the keepers so as to latch the door closed and to exert a further closing force on the door. Rotation of the pipe is achieved by a handle mounted thereto. The handle is within easy reach of a driver or other worker standing on the ground. The handle is normally held against the door by a retainer which is lockable while the van or trailer is in transit. The handle may be disengaged from the retainer and rotated away from the door. This rotation causes the cam or latch members to disengage the keepers and frees the doors for opening thereof.
It has been typical in the past where the above type of latching mechanism is used to mount or position, lift gates, lift gate extension plates, dock bumpers or the like below the level of the lower keepers. Such positioning member mounting locates the extension plate, dock bumpers or other member below the floor level of the van or trailer. This lack of coplanarity between the lift gate extension plate, dock bumper or the like, on the one hand, and the floor of the van or trailer, on the other hand, creates what is known as a "non-flush entry". In many work environments where the van or trailer is being loaded or unloaded, nonflush entry is unacceptable for cart operation. That is, many types of carts, hand trucks or other apparatus which are used to carry goods to the interior of the van or trailer traverse the nonflush entry with great difficulty or not at all.
It is not possible to mount the dock bumper, lift gate or the like in a coplanar fashion with the floor of the van or truck. Merely forming a hole through the dock bumper or other member, through which hole the lower end of the pipe and its cam or latch member extends would permit latching and unlatching but would not permit the doors to be swung open since the lower end of the pipe and the cam or latch member would continue to extend therebelow.
One technique that has been utilized in the past to avoid the above-noted problems and to permit a flush entry is to install an inside lock assembly on the interior of the panel doors. Not only does this approach not permit the doors to be positively latched in the same manner that is possible with exterior latching mechanisms, but also portions of the lock assembly may be damaged as the payload or goods within the van or trailer shift in transit.
An object of the present invention is the provision of a panel door latching apparatus which avoids the comings of the prior art noted above.